Explained: What are cloudbursts, and why they occur more in places like Amarnath

Source: The post is based on the article “Explained: What are cloudbursts, and why they occur more in places like Amarnath” published in Indian Express on 11th July 2022

What is the News?

Sudden highly-localized rains in Amarnath, Jammu and Kashmir have caused flooding and led to the deaths of at least 16 people. People called this as a cloudburst.

However, the Indian Meteorological Department(IMD) has said that a cloudburst may not have actually occurred.

What is Cloudburst?

A cloudburst refers to an extreme amount of rain that happens in a short period, sometimes accompanied by hail and thunder.

Criteria: The India Meteorological Department(IMD) defines a Cloudburst as unexpected precipitation exceeding 100 mm (or 10 cm) per hour over a geographical region of approximately 20 to 30 square km. 

Note: All instances of cloudbursts involve heavy rain in a short period but all instances of heavy rain in a short period are not cloudbursts if they do not fit this criterion.

Conditions during Cloudburst: The relative humidity and cloud cover are at the maximum level with low temperature and slow winds because of which a high amount of clouds may get condensed at a very rapid rate and result in a cloudburst.

Why do Cloudbursts occur in Hilly areas?

Experts have said it is difficult to predict when exactly a cloudburst will occur. But they are more likely to occur in mountainous zones mainly because of terrain and elevation.

This is because, in hilly areas, sometimes saturated clouds ready to condense into rain cannot produce rain due to the upward movement of the very warm current of air. 

Instead of falling downwards, raindrops are carried upwards by the air current. New drops are formed and existing raindrops increase in size. 

After a point, the raindrops become too heavy for the cloud to hold on to, and they drop down together in a quick flash.